/// <summary>
/// This function handles unsupported features by <see cref="Regen.Flee"/> evaluator by creating temporary
/// variables or even changing the type of expression.
/// </summary>
/// <remarks>
/// Because flee does not support arrays, we temporarly store any parsed array
/// into a variable and then just pass the variable name, letting Regen just fetch it
/// and pass it around.
///</remarks>
public Expression HandleUnsupported(Expression expr, List <TemporaryVariable> temps, Type caller = null)
{
//todo after we support dictionaries, add support here
switch (expr)
{
case NullIdentity _:
case CharLiteral _:
case NumberLiteral _:
case StringLiteral _:
case BooleanLiteral _:
case StringIdentity _:
case ReferenceIdentity _:
case EmptyExpression _:
return(expr);
case ArgumentsExpression argumentsExpression: {
for (var i = 0; i < argumentsExpression.Arguments.Length; i++)
{
argumentsExpression.Arguments[i] = HandleUnsupported(argumentsExpression.Arguments[i], temps, typeof(ArgumentsExpression));
}
return(argumentsExpression);
}
case ArrayExpression arrayExpression: {
for (var i = 0; i < arrayExpression.Values.Length; i++)
{
arrayExpression.Values[i] = HandleUnsupported(arrayExpression.Values[i], temps, typeof(ArrayExpression));
}
var parsedArray = Compute(arrayExpression, temps, typeof(ArrayExpression));
var temp = new TemporaryVariable(Context, parsedArray);
//todo this might lead to memory leaks!
//temps.Add(temp);
//if (caller == typeof(RegenCompiler)) { //if this is the first expression that is being parsed
// temp.MarkPermanent();
//}
return(IdentityExpression.WrapVariable(temp.Name));
}
case IndexerCallExpression indexerCallExpression: {
indexerCallExpression.Left = HandleUnsupported(indexerCallExpression.Left, temps, typeof(IndexerCallExpression));
indexerCallExpression.Arguments = (ArgumentsExpression)HandleUnsupported(indexerCallExpression.Arguments, temps, typeof(IndexerCallExpression));
return(indexerCallExpression);
}
case CallExpression callExpression: {
callExpression.FunctionName = HandleUnsupported(callExpression.FunctionName, temps, typeof(CallExpression));
callExpression.Arguments = (ArgumentsExpression)HandleUnsupported(callExpression.Arguments, temps, typeof(CallExpression));
return(callExpression);
}
case IdentityExpression identityExpression: {
//here we turn any string literal into a reference to a variable.
//if theres no such variable, we assume it is for a functionname of property.
if (identityExpression.Identity is StringIdentity sr)
{
if (Context.Variables.ContainsKey(sr.Name))
{
return(new IdentityExpression(ReferenceIdentity.Wrap(sr)));
}
}
identityExpression.Identity = HandleUnsupported(identityExpression.Identity, temps, caller ?? typeof(IdentityExpression));
return(identityExpression);
}
case HashtagReferenceExpression hashtagReference: {
var key = $"__{hashtagReference.Number}__";
return(new IdentityExpression(new ReferenceIdentity(key, new RegexResult()
{
Value = key, Index = hashtagReference.Matches().First().Index, Length = 1 + hashtagReference.Number.Length
})));
}
case GroupExpression groupExpression:
groupExpression.InnerExpression = HandleUnsupported(groupExpression.InnerExpression, temps, caller ?? typeof(GroupExpression));
return(groupExpression);
case PropertyIdentity propertyIdentity:
//todo maybe here we parse Left, store and push? but first invalidate that it is not just a name.
propertyIdentity.Left = HandleUnsupported(propertyIdentity.Left, temps, caller ?? typeof(PropertyIdentity));
propertyIdentity.Right = HandleUnsupported(propertyIdentity.Right, temps, caller ?? typeof(PropertyIdentity));
return(propertyIdentity);
case KeyValueExpression keyValueExpression:
keyValueExpression.Key = HandleUnsupported(keyValueExpression.Key, temps, typeof(KeyValueExpression));
keyValueExpression.Value = HandleUnsupported(keyValueExpression.Value, temps, typeof(KeyValueExpression));
return(keyValueExpression);
case NewExpression newExpression:
newExpression.Constructor = HandleUnsupported(newExpression.Constructor, temps, typeof(NewExpression));
return(newExpression);
case LeftOperatorExpression leftOperatorExpression:
leftOperatorExpression.Right = HandleUnsupported(leftOperatorExpression.Right, temps, typeof(LeftOperatorExpression));
return(leftOperatorExpression);
case OperatorExpression operatorExpression:
operatorExpression.Left = HandleUnsupported(operatorExpression.Left, temps, typeof(OperatorExpression));
operatorExpression.Right = HandleUnsupported(operatorExpression.Right, temps, typeof(OperatorExpression));
return(operatorExpression);
case RightOperatorExpression rightOperatorExpression:
rightOperatorExpression.Left = HandleUnsupported(rightOperatorExpression.Left, temps, typeof(RightOperatorExpression));
return(rightOperatorExpression);
case ThrowExpression throwExpression:
throwExpression.Right = HandleUnsupported(throwExpression.Right, temps, typeof(ThrowExpression));
return(throwExpression);
case ForeachExpression foreachExpression:
case ImportExpression importExpression:
case InteractableExpression interactableExpression:
case VariableDeclarationExpression variableExpression:
throw new NotSupportedException(); //todo support? this should be found in an expression. it is a higher level expression
case Identity identity: //this is an abstract class.
throw new NotSupportedException();
default:
throw new NotImplementedException();
}
}
/// <summary>
/// Perform the evaluation or translate <see cref="Expression"/> into a variable for later use in computation.
/// </summary>
/// <returns></returns>
private Data Compute(Expression expression, List <TemporaryVariable> temps, Type _caller = null)
{
return(_eval(expression, _caller));
Data _eval(Expression express, Type caller = null)
{
switch (express)
{
case null:
throw new NullReferenceException();
case ArgumentsExpression argumentsExpression: {
var arr = new Array();
foreach (var expr in argumentsExpression.Arguments)
{
arr.Add(_eval(expr));
}
return(arr);
}
case ArrayExpression arrayExpression: {
var arr = new Array();
foreach (var expr in arrayExpression.Values)
{
arr.Add(_eval(expr));
}
return(arr);
}
case NumberLiteral numberLiteral: {
return(new NumberScalar(_evaluate(numberLiteral.Value)));
}
case BooleanLiteral booleanLiteral: {
return(new BoolScalar(booleanLiteral.Value));
}
case CharLiteral charLiteral: {
return(new StringScalar(charLiteral.Value.ToString()));
}
case NullIdentity nullIdentity: {
return(Data.Null);
}
case StringLiteral stringLiteral: {
return(new StringScalar(stringLiteral.Value));
}
case KeyValueExpression keyValueExpression: {
//todo create a KeyValue regen data type.
return(new NetObject(new KeyValuePair <object, object>(_eval(keyValueExpression.Key), _eval(keyValueExpression.Value))));
}
case EmptyExpression emptyExpression: {
return(Data.Null);
}
case ForeachExpression foreachExpression: {
break;
}
case GroupExpression groupExpression: {
return(_eval(groupExpression.InnerExpression));
}
case ReferenceIdentity referenceIdentity: {
if (!Context.Variables.ContainsKey(referenceIdentity.Name))
{
return(new ReferenceData(referenceIdentity.Name));
}
if (!Context.Variables.TryGetValue(referenceIdentity.Name, out var value, true))
{
throw new Exception("This should never occur.");
}
//if it is not a reference, make one.
if (!(value is ReferenceData))
{
return(new ReferenceData(referenceIdentity.Name));
}
return((ReferenceData)value);
}
case PropertyIdentity propertyIdentity: {
TemporaryVariable tmp = null;
var left = _eval(propertyIdentity.Left);
if (left is ReferenceData rf)
{
var right = new PropertyIdentity(IdentityExpression.WrapVariable(rf.EmitExpressive()), propertyIdentity.Right).AsString();
return(Data.Create(_evaluate(right)));
}
//not reference
using (tmp = new TemporaryVariable(Context, left is NetObject no ? no.Value : left)) {
return(Data.Create(_evaluate($"{tmp.Name}.{propertyIdentity.Right.AsString()}")));
}
using (var var = new TemporaryVariable(Context, left is NetObject no ? no.Value : left)) {
var right = new PropertyIdentity(IdentityExpression.WrapVariable(var.Name), propertyIdentity.Right).AsString();
return(Data.Create(_evaluate(right)));
}
}
case StringIdentity stringIdentity: {
return(new ReferenceData(stringIdentity.Name));
}
case IdentityExpression identityExpression: {
return(_eval(identityExpression.Identity, caller)); //todo test
}
case Identity identity: {
throw new NotSupportedException();
}
case CallExpression callExpression: {
var left = _eval(callExpression.FunctionName, typeof(CallExpression));
var args = (Array)_eval(callExpression.Arguments);
if (left is NetObject || left is Array || left is Dictionary)
{
goto _storing;
}
//try regular parsing:
try {
var parsed = $"{left.Emit()}({args.Select(arg => arg.EmitExpressive()).StringJoin(", ")})";
return(Data.Create(_evaluate(parsed)));
} catch (ExpressionCompileException e) when(e.InnerException?.Message.Contains("FunctionCallElement: Could find not function") ?? false)
{
throw;
} catch (ExpressionCompileException) { }
_storing: //try storing left as variable
using (var var = new TemporaryVariable(Context, left is NetObject no ? no.Value : left)) {
var parsed = $"{var.Name}({args.Select(arg => arg.EmitExpressive()).StringJoin(", ")})";
return(Data.Create(_evaluate(parsed)));
}
}
case IndexerCallExpression indexerCallExpression: {
var left = Data.Create(_eval(indexerCallExpression.Left, typeof(IndexerCallExpression)));
var args = (Array)_eval(indexerCallExpression.Arguments);
if (left is NetObject || left is Array || left is Dictionary)
{
goto _storing;
}
//try regular parsing:
try {
var parsed = $"{left.Emit()}[{args.Select(arg => arg.EmitExpressive()).StringJoin(", ")}]";
return(Data.Create(_evaluate(parsed)));
} catch (ExpressionCompileException) { }
_storing: //try storing left as variable
using (var var = new TemporaryVariable(Context, left is NetObject no ? no.Value : left)) {
var parsed = $"{var.Name}[{args.Select(arg => arg.EmitExpressive()).StringJoin(", ")}]";
return(Data.Create(_evaluate(parsed)));
}
}
case NewExpression newExpression: {
//todo new
break;
}
case LeftOperatorExpression leftOperatorExpression: {
foreach (var e in leftOperatorExpression.Iterate())
{
if (e is ArrayExpression)
{
throw new NotSupportedException("Unable to compile a nested array, please define it in a variable first.");
}
}
//todo BuiltinTests.len fails here because we do not expand left or right. we should.
return(Data.Create(_evaluate(leftOperatorExpression.AsString())));
}
case OperatorExpression operatorExpression: {
foreach (var e in operatorExpression.Iterate())
{
if (e is ArrayExpression)
{
throw new NotSupportedException("Unable to compile a nested array, please define it in a variable first.");
}
}
//todo BuiltinTests.len fails here because we do not expand left or right. we should.
return(Data.Create(_evaluate(operatorExpression.AsString())));
}
case RightOperatorExpression rightOperatorExpression: {
foreach (var e in rightOperatorExpression.Iterate())
{
if (e is ArrayExpression)
{
throw new NotSupportedException("Unable to compile a nested array, please define it in a variable first.");
}
}
//todo BuiltinTests.len fails here because we do not expand left or right. we should.
return(Data.Create(_evaluate(rightOperatorExpression.AsString())));
}
case ThrowExpression throwExpression: {
break;
}
case VariableDeclarationExpression variableExpression: {
var name = Data.Create(_eval(variableExpression.Name));
if (name.GetType() != typeof(StringScalar))
{
throw new NotSupportedException("Variable names can contain only _azAZ0-9");
}
var value = Data.Create(_eval(variableExpression.Right));
Context.Variables[name.ToString()] = value;
return(value);
}
}
return(Data.Null);
}
}